This document discusses genotype by environment (G x E) interactions and their impact on plant breeding and yield. It defines G x E as the variation in relative performance of genotypes across different environments. The document notes that climate changes can threaten crop yields, so understanding how environmental factors affect growth is important. It explains that the phenotype is influenced by both the genotype and environment, and G x E interactions occur when a genotype's relative performance changes in different conditions. Several methods for analyzing G x E interactions are also presented.

1. PP 503: Physiological and molecular responses of
plant to abiotic stresses (2+1)
Large genotypes by environmental
interaction (G x E) for yield
Presented by:
Ekatpure Sachin Chandrakant
(PhD Research Scholar)

2. Definition
 The term GE interaction can be defined as the
variation in relative performance of genotypes
in different environments
 Term discovered by Allard and Bradshaw

3. Introduction
 Climate changes may result in strong impacts on
agriculture, specially on crop growth and yield
 Crops are largely determined by climate conditions
during growing season
 Even minor deviations from optimal conditions can
seriously threaten yield
 Therefore, knowledge on the effect of
environmental factors on crop growth and
development could reduce the possibilities of
significant yield loss and improve the selection of
specific cultivars for growing in the target regions.

4. Role of the environment in Quantitative
Inheritance
 The main result of this effect is that the relationship
between genotype and phenotype is partially or
completely hidden i.e. the phenotype doesn’t reveal the
genotype
 For e.g: Phenotype = Genotype + Environment ( P =
G + E )
 If environment = 0 then phenotype = Genotype
 However the effect of environment is seldom zero
 So phenotype is the joint action of Genotype and
Environment

5. Role cont…
 In crop improvement, the breeder selects plants on
the basis of their phenotype
 The effectiveness of selection depend on the
proportion of phenotype due to the genotype
 Therefore, it is important to know the extent to which
environment influences different quantitative
characters
 To estimate the effect of environment on a character,
large No. of strain / genotypes are grown in a
replicated trial and the data is subjected to analysis of
variance as per the experimental design used.

6. Role cont…
 The genotype x Environmental interaction
signifies that the relative performance of various
genotype in effected by the environment
 For eg: Performance of genotype ‘A’ may be
superior to the genotype ‘B’ in one environment
but in another environment inferior to that of ‘B’
 If G X E interaction is absent, genotype ‘A’ will be
superior than ‘B’ in all the environments

7. Methods for analyzing GE
interaction
In field crop trials, interaction is often analyzed by
 AMMI (additive main effects and multiplicative interaction)
model
 Analysis of variance (ANOVA)
 Principal component analysis (PCA)
 Genotype (G) main effect plus GE interaction (GGE)
 Biplot analysis
These models have been developed and applied over the
years to analyze GE interaction and especially yield
stability over environments in different crops

8. THANK YOU

9.  Seed yield per plant is one of the main yield
components which is greatly influenced by
genotype, environment and complex genotype by
environment interactions